From mboxrd@z Thu Jan 1 00:00:00 1970 From: rdunlap@xenotime.net (Randy Dunlap) Date: Wed, 10 Feb 2010 16:41:38 -0800 Subject: [RFC 0/2] fix dma_map_sg not to do barriers for each buffer In-Reply-To: <20100211093835I.fujita.tomonori@lab.ntt.co.jp> References: <1265834250-29170-1-git-send-email-adharmap@codeaurora.org> <4B7324D3.1000509@xenotime.net> <20100211093835I.fujita.tomonori@lab.ntt.co.jp> Message-ID: <4B735242.8000101@xenotime.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 02/10/10 16:39, FUJITA Tomonori wrote: > On Wed, 10 Feb 2010 13:27:47 -0800 > Randy Dunlap wrote: > >> On 02/10/10 12:37, adharmap at codeaurora.org wrote: >>> From: Abhijeet Dharmapurikar >>> >>> Please refer to the post here >>> http://lkml.org/lkml/2010/1/4/347 >>> >>> These changes are to introduce barrierless dma_map_area and dma_unmap_area and >>> use them to map the buffers in the scatterlist. For the last buffer, call >>> the normal dma_map_area(aka with barriers) effectively executing the barrier >>> at the end of the operation. >>> >>> Note that the barrierless operations are implemented for few arm >>> architectures only and I would implement for others once these are okayed by the >>> community. >> >> So when you add these interfaces for other architectures, you will also >> update Documentation/DMA-API.txt, right?? > > Seems that you misunderstand him. > > He is talking about other "arm" architectures. His patchset improves > arm's internal implementation (dma_map_area and dma_unmap_area are not > the DMA API; not exported for driver writers). He meant that the > patchset doesn't cover all arm architectures. > > This is about arm's implementation details and not related with other > non arm architectures. So no need to update Documentation/DMA-API.txt. OK, in that case I did misunderstand. Thanks for the info. -- ~Randy